The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 01, 1978
Filed:
Aug. 24, 1976
Yoshihisa Maitani, Hachioji, JP;
Kunio Shimoyama, Hachioji, JP;
Muneaki Yoshida, Hachioji, JP;
Akihiko Hashimoto, Hachioji, JP;
Masahiro Kitagawa, Hachioji, JP;
Olympus Optical Co., Ltd., Tokyo, JP;
Abstract
A photometric apparatus for single lens reflex camera and of the type in which an exposure value is determined by photometry of light which is transmitted through a photographic optical system and is reflected by at least one of the surfaces of a shutter blind and a film, said apparatus comprising a photoelectric transducer element for receiving light reflected by at least one of the surfaces of a shutter blind and a film, and an operational amplifier for biasing the photoelectric transducer element to maintain the voltage applied thereacross substantially null, thereby enabling a photometric output of the photoelectric transducer element to be effectively derived even when the amount of light received is minimal. A second photoelectric transducer element is provided for receiving reflected light from the reflecting mirror that is adapted to be switched between the viewfinder light path and the photographic light path and display means for displaying the operation of the shutter dependent upon the light which is incident upon the aforesaid second transducer element.